The shock absorbing hitches work pretty well. They really help on bumpy roads and are moderately good for stop and go traffic. You'll still feel it, it's just not as harsh.
As Brian said, check the fluid level. Low fluid may cause the actuator to extend too fast under accelration.
Brian is correct that the actuator itself is not a shock absorber, but most do contain some sort of shock absorbing system which varies depending on the brand of actuator. The Attwood actuator actually has a shock inside of it and the Tie Down Engineering actuator uses the brake fluid and a damper to dampen the speed of compression and extension of the actuator. When the brake fluid gets low, it starts to clunk, but will still stop fine. If the brake fluid is full, check your actuator for a shock. If it has rusted or lost a seal, it may start clunking. A correctly functioning actuator shouldn't be so harsh that you can feel a big clunk everytime you start.
(Message edited by csquared on June 17, 2003)